Qt Designer

shadcn-qt ships a Python custom-widget registration catalog. In Designer, widgets appear in a shadcn-qt group and can be dragged into forms, arranged with normal Qt layouts, and configured in the Property Editor.

Launch

PySide6 provides the supported Python plugin host used by pyside6-designer. The shadcn-qt launcher sets PYSIDE_DESIGNER_PLUGINS, PYQTDESIGNERPATH, and the binding selection before starting it.

pip install "shadcn-qt[designer]"
shadcn-qt-designer

Diagnostics:

shadcn-qt-designer --print-plugin-path
shadcn-qt-designer --print-command

If Designer is in a nonstandard location, set SHADCN_QT_DESIGNER to its executable.

Designer previews the light theme by default. Select dark mode or a custom JSON theme before launch:

SHADCN_QT_DESIGNER_THEME=dark shadcn-qt-designer
SHADCN_QT_DESIGNER_THEME=./brand.json shadcn-qt-designer

The preview stylesheet is scoped to shadcn-qt components and does not restyle Designer itself. The application still chooses its runtime theme with configure() / apply_theme().

Editable custom properties

Widget	Properties
Button	variant, shadcnSize, plus all QPushButton properties
Input / TextArea	invalid, plus inherited text properties
Card	elevated
Label / Badge / Alert / Toggle / Bubble / Toast	variant
Separator	orientation (horizontal or vertical)
Accordion / Collapsible	exclusive, title, expanded
Sheet / Sidebar	side, collapsed
Direction	direction (ltr or rtl)
Chart	chartType, comma-separated values
Typography	level (h1–h4, p, lead, code, and other presets)
Pagination / InputOTP	currentPage, pageCount, codeLength, value
Other widgets	Their normal Qt properties, such as checked, value, items, and currentIndex

Card, Alert, Tabs, TabPane, AspectRatio, Direction, Resizable, ScrollArea, and Sidebar are registered as containers. Normal Qt layout tools remain responsible for margins, spacing, stretch, and alignment.

Use the saved form

The same .ui file works with PySide and PyQt:

from shadcn_qt import apply_theme
from shadcn_qt._qt import QtWidgets
from shadcn_qt.designer import load_ui

app = QtWidgets.QApplication([])
apply_theme(app, "dark")
window = load_ui("mainwindow.ui")
window.show()

PyQt uses uic.loadUi; PySide uses QUiLoader with all shadcn-qt classes registered automatically. A complete example is in examples/python_designer.

Troubleshooting

• Launch through shadcn-qt-designer; a standalone Designer that is ABI-incompatible with the selected Python binding cannot load Python plugins.
• Check Help → About Plugins for import errors.
• Ensure the environment used to launch Designer can import shadcn_qt.
• Set SHADCN_QT_BINDING=PySide6 (or the intended binding) before importing any Qt module.